Method for producing an LED and LED produced by said method
View Patent ↗A light-emitting diode manufacturing method, including the successive steps of: a) forming an active layer including a stack of multiple quantum wells, each quantum well including a layer made of a semiconductor alloy; b) forming a trench for singularizing the diode, the trench crossing the active layer; and c) applying to the sides of the active layer, at the level of the lateral walls of the trench, a chemical treatment capable of etching a first component of the semiconductor alloy selectively over at least another component of the semiconductor alloy, wherein the bandgap width of the semiconductor alloy is a function of the concentration of the first component in the alloy.
1 . A light-emitting diode manufacturing method, comprising successive steps of:
a) forming an active layer comprising a stack of multiple quantum wells, each quantum well comprising a layer made of a semiconductor alloy;
b) forming a trench for singularizing the diode, said trench crossing the active layer; and
c) applying to sides of the active layer, at a level of the lateral walls of the trench, a chemical treatment capable of etching a first component of the semiconductor alloy selectively over at least another component of the semiconductor alloy, wherein a bandgap width of the semiconductor alloy is a function of a concentration of the first component in the semiconductor alloy,
wherein the chemical treatment applied at step c) is a wet treatment with a hydrochloric acid solution or an ammonium sulfide solution, and
wherein the chemical treatment applied at step c) results in a lower concentration of the first component of the first semiconductor alloy in a peripheral portion of each layer of the first semiconductor alloy, the sides of the active layer of the first semiconductor alloy remaining physically aligned with sides of layers of a second semiconductor alloy.
2 . The method according to claim 1 , wherein the bandgap width of the semiconductor alloy is all the larger as the concentration of the first component in the alloy is low.
3 . The method according to claim 1 , wherein the semiconductor alloy of the quantum wells is a ternary III-V compound.
4 . The method according to claim 1 , wherein the semiconductor alloy of the quantum wells is a quaternary III-V compound.
5 . The method according to claim 1 , wherein the semiconductor alloy of the quantum wells is indium gallium nitride or aluminum indium gallium phosphide.
6 . The method according to claim 1 , wherein at step b), the trench is formed by a dry etching method.
7 . The method according to claim 1 , wherein, at step b), the trench is formed by RIE or ICP etching.
8 . The method according to claim 1 , wherein step a) further comprises forming of a first semiconductor layer of a first conductivity type, on a side of a first surface of the active layer, and forming of a second semiconductor layer of a second conductivity type opposite to the first conductivity type, on a side of a second surface of the active layer.
9 . The method according to claim 8 , wherein the trench formed at step b) thoroughly crosses the second semiconductor layer and the active layer, and emerges onto the upper surface or into the first semiconductor layer.
10 . The method according to claim 1 , wherein said first component of the semiconductor alloy of the quantum wells is indium.